Due to the limits of green space in our expanding urban areas, we need to find creative solutions to incorporate nature into both our existing and new infrastructure. Green roofs are a smart way of utilising space in urban environments, and have many benefits apart from being aesthetically attractive.
The green roof boom
Over the past decade, green roofs have increasingly become embraced by many countries around the world. The green roof market in the UK is now expanding at a rate of 17% each year, while Germany is referred to as ‘the green roof capital of Europe.’ Rooftops across major cities in America have incorporated urban farms, communal spaces, and wildflower meadows, with some cities even introducing policies requiring all new buildings to have green roofs.
So, why are natural spaces such as green roofs becoming such a necessity for urban infrastructure?
The lack of green space in cities is now considered as a serious public health concern, as studies frequently demonstrate how vital nature is to our wellbeing. Humans depend on nature to survive, both physically and psychologically.
The Covid-19 outbreak has re-emphasised the importance of our outdoor environment and its impact on our health. More space for social distancing in a safe outdoor environment has never been so important for positively adapting to our changed ways of working and living. Aside from the social time we’ve been missing lately, being in the presence of greenery is critical to our immune system and mental wellbeing. Understanding the value of these benefits can help us design and improve infrastructure so that it can positively support us as humans and the natural ecosystem of our planet that we rely on to survive.
Important factors to consider for the delivery of a green roof project:
The location, structure, and vegetation are all major factors to consider when taking on a green roof system. In terms of location, the local climate, volume of rainfall and amount of sunlight will determine what is suitable. Structural factors include the load of capacity on the roof, the pitch, the height of walls, and access for installation. In addition, the depth required for plants, shade and drought tolerance, and environmental issues will ascertain the type of vegetation that can be used.
Types of green roofs
Green roofs can be constructed in various forms depending on the use and benefits required and will normally be intensive or extensive.
Intensive green roofs are often constructed to replicate ground level gardens for communal use, require deeper substrate/soil levels and will facilitate larger plants and even trees. Most businesses understand the need to create positive environments for their employees, and the resulting positive impacts this has on business performance. In Silicon Valley, outdoor meetings are commonly held on roof tops where you can find rest areas, eating and entertaining spaces and garden allotments. This movement will no doubt increase in pace due to the events that have unfolded so far in 2020.
Extensive green roofs are designed to be low maintenance and use thin layers of substrate resulting in lightweight construction. Their key benefit is bringing improved biodiversity to the built environment and they will support a large number of plant species that will tolerate fluctuating moisture levels. With the increased use of solar panels on rooftops, extensive green roofs can be used in conjunction with these providing additional environmental benefit.
Bringing it all together
As urbanisation rapidly increases, we need to quickly adapt and ensure we implement green solutions within the built environment to develop sustainably into the future. We are now more equipped with the products and supported services to facilitate the transformation of our urban infrastructure. Smart systems can be combined to maximise the environmental impact and are brought about by a network of green infrastructure such as green roofs, living walls, street trees and biodiverse planting schemes. It is exactly these types of ecosystem services that contribute towards our health, wellbeing and the environment that these depend upon.